This Fatal Flaw Could Crash the F-22 or F-35

An ancient Greek tale says that Icarus drowned in the Mediterranean Sea after he ignored his father’s advice to fly low to avoid the sun’s warmth during their attempted escape from the isle of Crete. He chose instead to soar upward on his manmade wings, where the sun melted the wax binding his feathers to his body and sent him plunging to his death. But it wasn’t so much heat, as hubris, that doomed him.

Adventurers have been trying to cheat the heavens ever since. And, as was the case with Icarus, aviation’s weak link is often the human at the helm.

Metal and carbon-fiber warplanes have been outflying their flesh-and-blood pilots for decades. I first got wind of this more than 30 years ago as a reporter for the Fort Worth Star-Telegram, where I covered the Fort Worth-built F-16 like white on rice. It seemed that the then-new hot fighter could fly so fast and turn so sharp that it could keep enough blood from a pilot’s brain to render him (they were all hims back then) unconscious in a matter of seconds.

Such human frailties have led to an alphabet soup of trouble, and how to avoid it: That G-induced loss of consciousness (GLOC) has led to the development of GCAS (ground collision avoidance systems). And there’s the latest cockpit option (with the worst acronym, which sounds a lot like the cute coveralls toddlers wear): the On-Board Oxygen Generating System, or OBOGS.

“Flying headlong into the ground is the single biggest killer of fighter pilots in the Air Force,” Air Force Magazinereported two years ago. “The phenomenon known as Controlled Flight Into Terrain (CFIT) is responsible for 75 percent of F-16 pilot fatalities and is often due to disorientation or loss of consciousness while maneuvering at low altitude.”

Of course, it’s part of the military’s DNA to, ahem, push the envelope. For pilots, that can mean flying longer missions from more austere bases—even if the cost isn’t worth it, and the need to do it is vanishingly tiny. But it’s that quest that has brought us OBOGS and its dangerous complications.

The systems, developed in the 1980s and now common on military aircraft, suck in thin air from the engine intakes. Then they purify, cool and concentrate it into a 95 percent oxygen gas to keep pilots alive and alert. The system replaces traditional liquid oxygen systems, which limited a pilot’s flight time, especially a problem in planes that can be refueled in midair. Such liquid systems also can’t always be resupplied at the primitive forward air bases the military says it may need to fly from in the next war, but hardly ever does.

Pilots of at least six different kinds of OBOGS-outfitted military aircraft have had trouble breathing in recent years. They range from hot planes like the Air Force’s F-35As, F-22s and A-10s, and the Navy and Marines’ F-18s, to the more modest Navy T-45 Goshawk and Air Force T-6 Texan trainers.

These so-called “physiological events” generally involve pilot impairment triggered by a lack of oxygen—hypoxia—that can quickly turn deadly because of the resulting dizziness, disorientation, decompression, numbness and pain. Most frustrating for all involved, the services have been unable to pinpoint the root of the problems. So they have been forced to rely on tweaking the systems, modifying their software, beefing up training, and crossing their fingers.

Both Air Force and Navy pilots have refused to fly airplanes they deemed to be outfitted with faulty OBOGS. Military officers—trained from Day One to follow orders—don’t take such steps lightly. What’s amazing about it is that military leaders, who are forever insisting the safety of their troops is one of their most sacred responsibilities, are having to be pushed to take action by their subordinates who fear for their lives.